Conventionally, there have been container refrigeration units for cooling an interior of a container used in marine transport or other transports.
Patent Document 1 discloses a container refrigeration unit of this type. The container refrigeration unit is provided in an opening of a container body one end of which is opened. In a lower part of a casing of the container, an external storage space communicating with an exterior of a container body is formed. The external storage space contains a compressor, a condenser, and an external fan, for example.
On the contrary, in an upper part of the casing, an internal storage space communicating with an interior of the container body is formed. At a rear surface of the casing, a partition plate is placed upright to partition the interior of the container body and the internal storage space. The partition plate is coupled to and supported by side stays (pillar members) respectively provided at both ends of the casing. In the casing, an air passageway is formed between a casing body partitioning the container into the internal side and the external side thereof, and a partition plate. The internal storage space is provided with an internal fan and an evaporator.
When the container refrigeration unit is operated, internal air is suctioned into the internal storage space by the internal fan. The air is cooled in passing through the evaporator. The cooled air passes through the air passageway, and is sent to the interior of the container again. As described above, the container refrigeration unit is configured to circulate the internal air while cooling the internal air in the air passageway, thereby freezing and refrigerating stored goods in the interior of the container.